- JDBC is designed to
access any database platform
- There is an
un-avoidable
system dependent
component in
accessing a database server:
- The communication protocol (messages exchanged between the JDBC and the database server) is different for different database servers
- The solution that JDBC has adopted to
support communication transparency
is through
communication drivers
Explanation:
- A
communication driver
is a
system dependent software module
that is written specifically according to a given
communication protocol
- Database servers from different vendors can provide tha same data service through different communication protocols
- A
communication driver
is a
system dependent software module
that is written specifically according to a given
communication protocol
- Result:
- Although the JDBC library is
a standard, there is
one component that is
system dependent:
- The JDBC communication driver (or JDBC driver)
- Although the JDBC library is
a standard, there is
one component that is
system dependent:
- Therefore:
- A JDBC program first
loads
a desired
communication driver
for that particular
system
(e.g., Windows, Linux, MacOS, etc)
- A JDBC program first
loads
a desired
communication driver
for that particular
system
- The developers of
JDBC had provided
a standard way to:
- Load
the
JDBC communication driver
into a Java JDBC program
The standard is implemented in the DriverManager class inside the java.sql package: click here
- Load
the
JDBC communication driver
into a Java JDBC program
- The DriverManager class:
- The DriverManager class in the Java library contains methods for managing a set of JDBC drivers.
Here is a link to the documentation: click here
- Methods in the
DriverManager class
that you need to use:
- static void
registerDriver
(Driver driver)
- Effect:
"Register" (= load)
the given driver.
(This method will install the driver code (passed as an object) into the JDBC program)
- Effect:
"Register" (= load)
the given driver.
- static Connection
getConnection
(String url,
String user, String password)
- Effect:
Attempts to establish a connection
to the given database
(given by URL).
- Method will return a Connection record containing information about the network connection.
You should only try to establish a network connection after you have registered a JDBC driver !!!
- Effect:
Attempts to establish a connection
to the given database
(given by URL).
- static void
registerDriver
(Driver driver)
- The way to
register (= load/read in) a
platform dependent JDBC driver
is to use the
registerDriver() method
in the DriverManager
class:
JDBCDriverObject = new DriverClass( ); // Create a driver object DriverManager.registerDriver( JDBCDriverObject ) ;Note: programmers often use the following shorter construct:
DriverManager.registerDriver( new DriverClass( ) );
- Syntax to
register the
MySQL JDBC driver:
DriverManager.registerDriver( new com.mysql.jdbc.Driver() );
- Registering/Loading the
JDBC driver in
Oracle:
DriverManager.registerDriver( new oracle.jdbc.driver.OracleDriver() );